Comparitve analysis of dry and wet processing of coffee with respect to quality in Kavre District, Nepal

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COMPARATIVE ANALYSIS OF DRY AND WET PROCESSING OF

COFFEE WITH RESPECT TO QUALITY IN KAVRE DISTRICT, NEPAL

A research project submitted to Larenstein University of Professional Education in Partial Fulfillment of the Requirements for degree of Master of Agricultural Production Chain

Management, specialization in Post-Harvest Technology and Logistics

By

Raghu Nath Subedi September 2010

Wageningen The Netherlands

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i PERMISSION TO USE

In presenting this research project in partial fulfillment of the requirements for a postgraduate degree, I agree that the Library of this University may make it freely available for inspection. I further agree that permission for copying of this research project in any manner, in whole or in part, for scholarly purposes may be granted by Larenstein Director of Research. It is understood that any copying or publication or use of this research project or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University in any scholarly use which may be made of any material in my research project.

Requests for permission to copy or to make another use of material in this research project in whole or part should be addressed to:

Director of Research

Larenstein University of Professional Education P. O. Box 9001

6880 GB Velp The Netherlands Fax: +31 26 3615287

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ii ACKNOWLEDGEMENTS

It is my great opportunity to express sincere and deep sense of gratitude to Dr. Tracey Campbell, my thesis supervisor and lecturer, Van Hall Larenstein for her proper guidance, constructive suggestions, keen interest, encouragement and full inspirations during the entire period of thesis writing.

I would also like to express sincere thanks to my course coordinator, Dr. Robert Baars, for his valuable suggestions, recommendations, and encouragements while writing my thesis proposal and also for his valuable lectures during research module. Furthermore, my sincere thanks go to all the Larenstein teachers, staffs and class fellows who assisted me to make my stay pleasant in Wageningen.

I am extremely thankful to Mr. Hom Raj Giri, President of District Coffee Producers’ Association (DCPA), Kavrepalanchok, Mr. Naba Raj Sapkota, facilitator, DCPA, respondents (farmers, processors, traders and local roasters) of Kavre district, Coffee Promotion Programme, National Tea and Coffee Development Board (NTCDB), Everest Coffee Mill, Gauri Shankar Organic Coffee Shop for providing relevant information. It is not possible to complete my work on time without their support.

I cannot forget to gratitude my father and mother for their utmost cooperation, inspiration and encouragement during the entire period of my study.

I would like to express deep gratitude to Dutch Government for granting fellowship for my study in the Netherlands.

Last but not the least; I would like to present a very special thanks to my colleagues, Mr. Dawa L. Sherpa, Mr. Jimmy A. Bolanous and Mr. David Kintu for their valuable supports and constructive comments during proposal and thesis writing.

Raghu Nath Subedi September, 2010 Wageningen

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The problem of this research study was variation in quality of coffee obtained from two processing method that has affected export market. This study was aimed to compare and analyze two processing methods with respect to quality. It also has tried to recommend the one with best that ensures good quality for the export market.

The study was conducted at Panchkhal VDC in Kavre district through case studies with seven chain actors (2 farmers, 2 processors: dry and wet, 2 traders and 1 local roaster) and survey with 30 respondents (10 farmers, 5 processors, 5 traders and 10 consumers). Six chain actors (except local roaster) who were selected for case study were taken from the 30 respondents involved in survey. The research was mainly based on qualitative and few quantitative approaches. The whole research study took three months (July-September) to complete. Detailed case studies with seven chain actors was done through semi-structured interview with a checklists prepared for each actor. Survey was done with multiple choice questions as checklists for interview.

Moisture content in the green bean of different samples was measured by using digital moisture meter. Standard commercial moisture range (9-12%) recommended by International Coffee Organization (ICO) was referred to compare the moisture percentage of green bean. Survey for cup taste test was done to find out the taste difference between coffees processed from two methods. The data obtained were analyzed using Excel and SPSS. Benefit-cost ratio for each method was also calculated based on the data available from National Tea and Coffee Board (NTCDB).

It was found from the case study with wet processor that 70% of total coffee produced in the district was processed through wet method. In dry processing, sorting and grading of cherries and drying were found to be critical control point (CCP). Similarly, sorting and grading of cherries, fermentation, and drying were CCP assumed in wet method whereas sorting and grading of green beans and roasting were the common CCP for both methods. The optimum level of moisture recommended by the processors for dry cherry, parchment and green bean was 11-12% for storage up to four months. The optimum time duration for fermentation of parchment was 24-72 hours depending on the weather conditions. Critical control limits for roasting was at 200-250oC temperature and for about 10-15 minutes respectively.

The average moisture content of green bean taken from different lots from dry method was found to be 12.83% which was a bit higher than the standard moisture range (9-12%), whereas moisture content of green bean from wet method was within the range i.e. 11.7%. Out of 30 respondents surveyed, 24 respondents rated ‘very good’ for the cup of coffee processed from wet method and reported that the cup had an excellent fruity aroma (at 5% significance level, p = 0.001).

Majority of the respondents (43%) reported that moisture content and flavour are the major determinants of coffee quality. Determination of moisture content was found to be the most reliable method followed by laboratory reports. Similarly, 33% respondents considered coffee processing step as an important value chain function determining coffee quality followed by selection of good nursery (27%). Knowledge and training was the major influencing factor for

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quality coffee production followed by supply of quality input. The respondents criticized that the main reasons for adopting two processing methods was processors inaccessibility to get credit to buy pulping machine as well as lack of proper training on processing of coffee.

Benefit cost ratio for dry method was found to be higher (1.4) than wet method (1.2). Wet method was found to be more advantageous than dry method based on sustainability of quality coffee production. The main problem associated with dry method was risk of secondary fermentation due to insufficient drying of cherries. Under and over fermentation, troubleshoot in pulping machine and water pollution were the major problems associated with wet method. It was concluded from the research study that method of processing has more impact on coffee quality. Moisture content, aroma, taste, flavour and acidity are important quality attributes and are the major factors determining coffee quality. Coffee with pleasant aroma and purer flavour was obtained from wet processing method. Wet processing was found far better than dry one with respect to quality of coffee.

Finally wet method of processing was recommended for the processors to produce quality coffee for the export market. Establishment of pulping centers, standardization of processing method, chain coordination, increased accessibility of farmers and processors to get credit and capacity building of coffee chain actors through knowledge and training are recommended to increase and maintain the quality of coffee through wet processing method.

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1 CHAPTER 1. INTRODUCTION

1.1 Introduction to the thesis

This study has been carried out as a final thesis research for the partial fulfillment of the course requirements of Master in Agriculture Production Chain Management, specialization in Postharvest Technology and Logistics at Van Hall Larenstein, University of Applied Sciences in Wageningen. This research report gives insight into comparative analysis of dry and wet processing methods of coffee with regards to quality in coffee value chain. This research was carried out in Kavre district, Nepal.

This thesis report consists of 6 chapters. The first chapter gives an introduction and background of Nepalese agriculture and coffee in Nepal. This chapter also includes the objective of the research study, the main research questions and sub-questions for research. Chapter two gives the literature related to coffee production, processing, marketing and major concerns about analysis of quality management aspects regarding coffee processing techniques. The third chapter covers the methodology which mainly includes the research design, sampling procedures and data analysis techniques, selection of the study area, presents brief introduction of the study area. Chapter four and five describe the results of the data collection and discussions on the findings respectively. Conclusions and recommendations are mentioned in chapter six.

1.2 General background 1.2.1 Nepalese agriculture

Nepal is an agricultural country where 65% of the total economically active populations are engaged in agriculture. The share of agriculture in national gross domestic product (GDP) is 39%. The government of Nepal has clearly described and placed agriculture in a priority sector since tenth five year plan as poverty alleviation strategy. Still 31% of total populations live below poverty line, less than one dollar per day. This widespread poverty in country is mainly due to the traditional agricultural system. Therefore, commercialization of agriculture with higher growth rate is a good way to reduce poverty in Nepal. Modernization and increased access of farmers to modern agricultural inputs and credits is a good way to increase the agricultural growth rate (NPC, 2009).

Nepal is natural paradise because of its climate and biodiversity with diverse ecosystems ranging from tropical plains to high Himalayas. The biodiversity of crops, livestock and fisheries is vital to marginalized rural communities for maintaining food security and livelihoods. Rural Nepal with 86% of total population has extreme variation in altitude, a complex topography, and diverse climatic conditions and integrated farming systems. Agriculture, services, small scale manufacturing industries and tourism, including remittances, are the major sources of income, employment and livelihoods. Industrial activities mainly involve processing of agro-products. The major export items include woolen carpet and garments followed by agricultural products like pulses, jutes, medicinal herbs and leather products. Niche products and commodities such as tea, coffee, ginger, honey and off-season vegetables have shown high export potentials in the recent years (Shrestha et al., 2007).

In order to enhance the growth in agricultural sector in Nepal, the government has put into operation the 20 years strategic plan, Agriculture Perspective Plan (APP, 1995-2015). APP has been regarded as worth seeing to raise AGDP growth rate from 3% to 5% by the end of 2015

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(APP, 2008). Therefore to achieve the targeted growth rate in agriculture, APP has mainly given emphasis on the production of high value cash crops (tea, coffee, ginger, cardamom) through pocket package program.

1.2.2 Coffee in Nepal

Coffee is one of the high value cash crops grown in Nepal with potential high quality for domestic as well as international niche market. Among the various cash crops for commercialization, coffee is emerging as a likely agro-enterprise with great potential to provide farm employment and income generation opportunities in the mid hills of Nepal (CoPP, 2007).

Coffee can be well grown to the climate of mid-hills of Nepal and is emerging as one of the potential cash crops to provide rural farmers with on-farm employment. Superior highland organic coffee for niche export market can be produced above 800 m altitude from sea level. However, being a new crop to Nepal, coffee production and processing technologies are still in a rudimentary stage. Considering its potential for poverty reduction of rural mid-hills people, both governmental and non-governmental organizations have initiated research and development works in coffee (Shrestha et al., 2007).

In Nepal, coffee can be grown from low to mid-hills (800-1600 m asl) covering about 60,000 hectare of land. Most suitable are the northern slope along this altitude range. The coffee grown above 800 meters is labeled as highland coffee, which if grown and processed correctly, will have high quality and flavour. Since even smallholders can grow coffee in their marginal lands, coffee expansion holds promise for effective poverty reduction, the main goal set by the 10th Five Year Plan of the country (Koirala, 2003).

Coffee is cultivated in Nepal with no use of synthetic fertilizers and pesticides. This crop has an important occupation in the rural economics with massive participation of marginal, poor and down trodden class of rural communities, and has contributed for the soil conservation, bio-diversity maintenance and watershed balance in the mid-hills of Nepal. Coffee farming in Nepal is proven as promising due to the availability of soil with good structure (physical and chemical) and appropriate micro-climate in the mid hills (Nepal, 2006 as cited in Poudel et al., 2009). Coffee is processed either by wet method to produce parchment coffee or by dry method to obtain cherry coffee. In Nepal, dry processing was predominantly practiced in the past (10 years ago). But nowadays, this method has gradually been replaced by wet processing method. Wet method has also becoming more popular and been introduced for export of green beans (Deoju and Manandhar, 2004).

1.3 Research problem

The major problem currently facing Nepali coffee production is the great variation in the quality of dried coffee beans. The problem comes from the fact that the coffee beans are collected from the many small scale farmers and, in the absence of quality standards for coffee, this has led to variation in quality. There are a number of reoccurring processing errors in both dry and wet processing systems. By removing many of these errors, it would be possible to significantly improve the quality of the coffee (ECIBON, 2009).

The quality and productivity of coffee is low at the farmer’s level. Lack of organized cherry collection system is leading to lower quality green beans entering into the market and primary producers are exploited by the traders. There is a high post-harvest loss at the farmers, and

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processors level due to high sorting and grading losses. Processing 100 kg of fresh cherry yields about 12.5 kg of green beans which about 50% lower than the world average yield of Arabica coffee (Bajracharya and Pathak, 2004).

Coffee is a complex product with attributes (flavour, acidity, body, and aroma) that emerge from a combination of these characteristics displaying a rich variability of that cannot be totally disintegrated. These natural variations of coffee that complexly produce the final quality relate to different coffee varieties, soil altitude and rainfall conditions and cultivation and processing methods used by producers in different producing regions (Roseberry, 1996 as cited in Donnet and Weatherspoon, 2006). These factors can contribute to rich attributes that signal the sensory quality of coffee. These quality attributes thus enhance the sensory evaluation of the product. It is well accepted that green coffees resulted from the wet method which is called as washed Arabicas yield roasted beans and coffee beverages, respectively, that are characteristically different from those produced from the dry method- the so called unwashed Arabicas. There is no doubt, that these flavour differences in part have to be attributed to difference in the thorough processing applied during either of the two methods due to the fact that only fully ripe coffee cherries are used for wet processing, whereas fruits of all stages of ripeness are utilized by dry processing. During post-harvest treatment, various metabolic processes occur inside the coffee seeds which significantly alter the chemical composition of the green bean resulting in differences in cup quality (Knopp et al., 2005).

The decisive quality criterion of coffee as a beverage is its aroma being composed of more than 800 compounds. Amazingly, only about 30 of these contribute significantly to the specific coffee aroma. These aroma impact compounds are suitable indicators to estimate objectively the aroma differences resulting from different processing methods. Till now, the reasons for the quality differences of technologically distinctively produced coffees are unknown. In this context, the biochemical and physiological processes which occur in the living coffee bean during postharvest processing, and which are related to quality, must be taken into consideration (Bytof

et al., 2000).

These two common processing methods are practiced by the coffee processors in the Kavre district. The quality of coffee produced from these two processing methods has some differences which is not clear. Coffee importers always claim differences in the coffee quality processed by the two methods, whether this difference exists significantly or not has yet to be analyzed through research. This has been a major concern from a quality management perspective. Therefore to maintain the quality of coffee through these two processing methods is very important especially for the export market and of course is interesting issue for research. The problem owners in this research are coffee processors and traders.

1.4 Justification

Quality control measures (time between harvest and pulp, duration of fermentation, type of water used to wash the parchment, optimum drying of parchment and beans) are applied by the processors at various steps in coffee processing. The control measures are applied as per the perception of the individual actor and objective measurements (moisture percentage, acidity, number of defective beans) are done. There is no systematic and uniformity in the application of these control measures throughout the chain. Most of the coffee chain actors in Nepal are unaware of quality management system except for the organic certification which is being sought by the importing clients (Munankami, 2004).

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Though both methods are aimed at removing the fruit flesh of the coffee cherry and reducing the water content in the raw coffee beans to about 10-12%, it has been realized that some factors such as grading and the homogeneity of the material affect the quality of the final product. The differences in the cup quality between coffees processed from dry and wet method has been the major concern for the coffee importers and quality experts (Bytof et al., 2004).

Application of dry and wet processing techniques of coffee by the processors has certainly led to differences in the quality to some extent. If the qualities of coffee processed from these two methods get difference significantly, then the market will be affected. Customers always want coffee with uniform quality and in consistency that will fetch higher price in market. So it is necessary to assess the quality through comparative analysis between the two methods and recommend one to the processors that is economically and technologically sound.

1.5 Research objective

To compare and analyze the two processing methods of coffee in Kavre district in terms of quality and identify one which is more feasible both economically and technologically. 1.5.1 Research questions

i. What are the quality criteria for coffee to be considered in both dry and wet processing methods?

- What are the steps followed in both processing methods?

- What are the minimum quality criteria for coffee for the local and export market? - What kind of quality measures are the processors practicing in both methods? - What are the critical control points (CCP) at processing level for coffee? - Which method of processing is widely practiced by farmers?

ii. Which method of processing is more recommendable both economically and technologically?

-What is the B/C ratio of each processing method?

-What are the advantages and disadvantages of both methods? -What are the problems in both processing methods?

-What recommendations can be given to use one type of processing techniques? 1.6 Definition of concepts

Fresh cherry: Fully matured fruit in the coffee plant ready to harvest. Dry cherry: Coffee cherry dried after harvest up to moisture level of 12%.

Wet parchment: When fresh cherry is depulped within 24 hours after harvest, then the coffee produced is called wet parchment.

Dry parchment: This is the coffee obtained after complete fermentation (free from mucilage) and drying of wet parchment. It has a moisture range of 11-12%.

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Green bean: This is the product obtained after hulling the dry parchment which contains standard moisture range of 11-12% and is ready for the export market. The colour of the green bean is bluish green in colour.

Quakers: They are the defective coffee green beans that fail to roast properly, remaining stubbornly light-coloured.

Stinkers: They are also the defective green beans. When they are cut, release a putrid, nauseating odour, which is also volatile and the odour will have disappeared after a few hours. It is often difficult to distinguish this kind of bean with healthy one because the appearance is no or slightly difference between two. The bad odour ultimately results in unpleasant taste (Mutua, 2000).

Specialty coffee: Specialty coffees are high quality coffees that differ from normal coffee with relevance to visual quality or cup or both. Specialty coffee in the green bean phase is defined as it has distinctive trait without defects in the cup. They are getting increasingly popular in the world coffee market (Deoju and Manandhar, 2004).

Quality: It is defined as product performance that results in customer satisfaction and freedom from deficiencies, in short fitness for use. Therefore, quality is meeting or exceeding customer and consumer expectations (Luning and Marcellis, 2009).

Value chain finance: Value chain finance is when one or more financial institutions link into the value chain, offering financial services which build on the relationships in the chain. The seller, buyer and the financial agent works together in a triangular cooperation, using the business relations in the value chain as a career to provide financial services (KIT and IIRR, 2010). 1.7 Scope and limitation of the study

The study was conducted in August 2010 when new coffee cherries were still on the tree and the case study was conducted with the respondents (processors and traders) who usually had green beans in stock ready for the export and local market.

The study was done on the basis of existing situation of the village development committee (Panchkahal VDC) in Kavre district and coffee produced by few respondent farmers was followed through the chain. Therefore, the results obtained may not reflect and represent coffee growing situations of the whole country.

The survey will focussed more on the qualitative issues rather than quantitative figures of actual yields and post-harvest losses that occurred during the various processing activities. The stakeholders’ boundary in the supply chain excluded the breeders and retailers.

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6 CHAPTER 2. LITERATURE REVIEW

2.1 Coffee production and consumption in world

Coffee is the world’s most popular beverage after water and it is the second most traded commodity after raw oil. The vast majority of world coffee is the Arabica species. Global production of coffee has reached to 124, 064, 000 bags (60 kg/bag) of green bean in 2009. This has been decreased by 3.2% as compared to production of 128, 183, 000 bags in 2008 (Figure 2.1). Similarly world coffee exports reached to 94.7 million bags in 2009 as compared to 97.6 million bags in 2008. The decrease in the coffee export is due to world economic crisis. Brazil is the largest producer and of coffee followed by Vietnam and Indonesia while in terms of export share, Brazil is ranked in first followed by Vietnam and Columbia (ICO, 2010). Country wise coffee production and their export share are presented in Figures 2.2 and 2.3 respectively.

Figure 2.1 World coffee production and consumption (source: ICO, 2010)

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Figure 2.2 Country wise share of coffee production in the world (source: ICO, 2010)

Figure 2.3 Export share of major coffee producing countries in the world

(source: ICO, 2009)

2.2 Coffee production, processing and marketing in Nepal

Coffee is emerging as one of the potential crops to provide rural farmers with on-farm employment and income and is well suited to the climate of mid-hills of Nepal. Superior highland organic coffee for niche export markets can be produced at an altitude higher than 800 meters.

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However, being a new crop in Nepal, coffee production and processing technologies are still in a rudimentary stage. Considering its potential for poverty reduction of rural hill people, both government and non-government organizations have initiated research and development works on coffee (Shrestha et al., 2008).

2.2.1 Area and production

In Nepal, the total areas under coffee cultivation, as well as, total yield have been increasing over the last decades. Over the period 2000 to 2008, the cultivated area has increased almost five-fold and the production of green bean almost seven fold while the export volume has increased by more than 90%. The total area under cultivation in 2008 was 1495 ha (Figure 2.4) and the numbers of growers were 20,000. The total production and export of green beans were 233 mt and 140 mt respectively in the year 2008 (Figure 2.5). The average yield of green bean is 183 kg/ha which is comparatively lower than the major coffee producing Asian countries like India, Vietnam and Indonesia (NTCDB, 2009).

Figure 2.4 Coffee production area in Nepal

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Figure 2.5 Production and export of coffee in Nepal (Source: NTCDB, 2009)

2.2.2 Market and price

Domestic market for Nepali coffee is confined to tourists, residential expatriates, recognized offices (I/NGOs), some hotels and restaurants. Marketing of Nepalese coffee is primarily done through direct supply to departmental stores, trekking agencies and restaurants. The recent export trend of Nepalese coffee has been very encouraging. Japan, USA, and major EU countries (Germany, UK, Netherlands and Spain) are the major export markets for Nepalese coffee. In 2008/09 Nepal exported 127 mt of green bean mainly to Japan, Holland, UK, Germany and United States (ECIBON, 2009).

The niche in organic and specialty highland organic coffee offers real opportunities in terms of price. The trend of coffee price was in increasing till 2007 and suddenly dropped due to world economic crisis in 2008/09. The present price structure of coffee produced in Nepal is relatively higher as compared to the international market price due to specialty nature of Nepali coffee which is penetrating in to the market. India, Sri Lanka, Vietnam and Indonesia are major competitors of Nepali coffee in Asia (CoPP, 2009).

2.2.3 Coffee production in Kavre district

Coffee is a relatively new crop in the Kavre district. This is the second largest coffee producing district in Nepal. The favourable microclimate and geography has been beneficial for coffee cultivation. The total area under coffee cultivation was 130 hectares of land followed by 29 mt of dry parchment in 2008 (DCPA, 2009). Coffee production and cultivation for the last five years is shown in Figures 2.6 and 2.7. The productivity is still lower because many of the coffee trees are still too young to yield fruits.

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Figure 2.6 Coffee Production in Kavre district (Source: DCPA, 2009)

Figure 2.7 Coffee cultivation in Kavre district (source: DCPA, 2009)

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11 2.3 Processing of coffee

In Nepal, about 70% of the coffee produced is processed by wet method, but farmers in rural areas are still practicing dry method as they are not being easily accessed by transportation to sell their fresh cherry to the pulping centres. Most of the pulping centres are managed and run by farmers’ groups, cooperatives, and coffee producers’ association or by processor. Wet method requires more care than dry one which enhances the bean appearances thus rendering the batches more valuable (CoPP, 2005). Both the techniques consist of a series of operation which is presented in Figure 2.8.

The pulp containing water and sugar, the moist parchment skin and beans all would ferment rapidly, moulder or rot if transported or stored as fresh. The entire coating i.e. covering of the pulp, mucilage, parchment and the silverskin of the actual seed of the coffee fruit must be removed and the beans dried and cleaned to make it ready for the final consumption (CPC, 2007).

2.3.1 Dry Processing of coffee

In dry method, whole cherry is dried and when this is finished, the pulp and the parchment are removed in one single operation. This is simple method which includes less labour cost. The cherries are either sun-dried or machine dried with the outer fruit intact until the fruit gets moisture content of 12%. After drying they are de-hulled mechanically, producing beans that are characteristically lower in acidity, sweet, smooth and more complex in flavour than wet processed coffees (Wanyonyi, 1999).

Under Nepalese conditions, where the coffee growers are predominantly small holders who grow limited number of coffee plants, dry method is common in practice, but this has been gradually been replaced by the wet processing ones due to more demand on international market (Deoju and Manandhar, 2004).

Although there are fewer operations involved in dry processing than in wet processing, this method is more time consuming as drying cherries takes longer time than drying parchment. The risk of secondary fermentation is greater due to the presence of mucilage which is very hygroscopic (Coste, 2003).

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Figure 2.8 Successions of operations in dry and wet processing of coffee (Source: Coste, 2003) Export market Fresh Cherries Sorting Pulping Fermentation Parchment removal/Hulling Washing Hulling Drying Polishing Sorting-Grading Packaging Shipping/Export Dry processing Wet processing Cherry coffee Parchment coffee Roasting Grinding Packaging Brewing Domestic market

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13 2.3.2 Wet processing of coffee

In this wet method, the pulp is separated from the parchment. In this way slippery mucilage is exposed which is commonly removed by a process commonly called fermentation. This is followed by drying and washing of the beans in the parchment. Removal of parchment by hulling gives the clean coffee. The many steps in the wet method of coffee processing make it rather expensive but, if properly carried out, it gives a very high quality coffee (Wanyonyi, 1999).

In Nepal, wet processing technology has been introduced recently for quality export of green beans. Several wet processing plants are established in the major coffee producing areas of the country. The major steps involved in this method are described as follows:

2.3.2.1 Harvesting

Coffee is generally harvested when berries turn dark red colour which is about 8-9 months after flowering has taken place. The harvest generally starts from October and continues up to March. Ripe fruit can be plucked by hand, or picked with small rakes, or else with poles depending up on the availability of the labour (CPC, 2007).

2.3.2.2 Cherry sorting and grading

The cherry is sorted out before pulping. This helps to eliminate the immature, diseased, pest damaged and dry cherries as well as the leaves, twigs and other foreign materials present. The sorted out quality coffee cherries are the subjected to pulping to remove the outer layer. (Mutua, 2000).

Grading of fresh harvested coffee is done based on ripeness. Ripe and unripe cherries are separated to facilitate processing and to obtain a better product quality. Sorting and grading in wet processing can be done in washing vats. Foreign matters as well as cherry of different ripeness and dryness are separated in a washing vat due to their differences in density. Stones and heavy impurities are removed from the bottom; hard, partially dried cherries float and are discarded from the top (Willson, 1999).

2.3.2.3 Pulping

It is the process of mechanical removal of the pulp from the fresh cherry to have parchment coffee. The flesh and skin of the fruits are left on one side and the beans, enclosed in their parchment covering, on the other side (Annex A). The lighter immature beans are then separated from the heavier, mature beans through specially designed washing channels or by shaking the beans through a strainer into a tank of water (Hicks, 2002).

2.3.2.4 Fermentation

It involves the process that allows the mucilage layer on the parchment to be washed off easily. The beans are stored in fermentation tanks for 2-3 days depending up on the weather condition during which time, the slimy layer of the berry is separate from its parchment like covering, by natural enzymes. Completion of fermentation is determined by washing a bit of the parchment with clean water and then feeling the coffee with the hand. A gritty feel is an indication of the completion of fermentation. Different chemical products like lime, alkaline carbonates can also be used for removal of the mucilage which precipitates the pectines in the form of soluble pectates, which are then easily removed by washing (Mutua, 2000).

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14 2.3.2.5 Soaking and washing

After the completion of fermentation which can be found out by gritty feeling, not slippery, the coffee beans are then washed without delay to remove the fermentation break-down products. Delay or insufficient washing at this stage can produce undesirable flavours in final product. Fully wet parchment coffee has a moisture content of 50-54%. Soaking of parchment under water after complete fermentation for about 12 hours helps in improving the quality of coffee both in colour and taste. The fermented parchment is subjected to wash thoroughly in order to remove the degraded mucilage and acid before soaking (Wickramasinghe et al., 2001).

After fermentation and soaking, the parchment coffee is again washed with clean water to remove any dirt or remains of mucilage or sugars. Final washing is done in concrete channels by pushing the parchment with wooden paddles against a stream of water. About 100 liter of water is used in order to wash 10 Kg of parchment.

2.3.2.6 Drying

The main propose of drying is to maintain the moisture content of the parchment optimum for storage. Freshly pulped coffee has a moisture content of about 55% and that has to be reduced by drying to 11%. This is the ideal level of moisture content required for proper storage, hulling and roasting. In most of the developing countries, sun drying is predominantly used and mainly by the producers’ organizations/cooperatives, and the coffee is spread on the wire mesh tables for normally about two weeks in sunny days, until fully dry. Few commercial companies use mechanical drying method (Mutua, 2000).

If drying is carried out too rapidly, ‘case hardening’ may occur which is common in the drying of many grains. The surface is overdried and shrinks irreversibly to prevent easy movement of moisture from within the bean in an outward direction. Worse than this, the bean may become pale and bleached in appearance signifying flavour deterioration. Field evidences have shown that when drying is done too rapidly under excessively warm temperatures, the valuable cup flavour is largely lost from coffees that otherwise would have been considered excellent (Sivetz and Foote, 2004).

2.3.3 Common steps for both methods

2.3.3.1 Hulling

This is the process of removing husk either from the dry parchment coffee or dry cherry in order to give the commercial green coffee. When the coffee gets to this stage, all intrinsic quality (moisture content, colour) has already been obtained. The different sorting techniques to which it is subjected can only reduce its percentage of defects in coffee beans. Hulling is achieved by creating friction among the beans lying along the screw of machine. It is crucial not to heat the beans during hulling otherwise it will affect the final colour and taste of coffee. There is another final layer closest to bean, called as silverskin, which may or may not be removed during hulling process. For removal of silverskin, separate equipment following hulling called polishers is needed. The green bean received is then subjected for sorting according to density, size and colour (Wanyonyi, 1999).

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15 2.3.3.2 Bean size sorting

Sorting of green beans is an important operation during coffee processing which also facilitates to carry out roasting. Roasting is carried out with beans of similar size, if not done, the beans with smaller size get burned earlier while the larger ones get insufficiently roasted. Larger beans also fetch premium price in the market and ultimately beans with higher percentage of defects get concentrated in low grade coffee (Mutua, 2000).

The green beans are sorted according to size, density and colour. Manual sorting, which is tedious and labour intensive, is practiced in Nepal. Machine sorting is also used by some trading companies. Machines for size sorting use the sieving principle which is either one using screens mounted in the drums or the vibrating flat bed of rectangular shape (NTCDB, 2009). Electronic colour sorting is used to separate beans with an undesirable colour, such as black, white or brown beans.

2.3.3.3 Roasting

This is the most critical stage during postharvest handling of coffee. The main purpose behind roasting is to release the aroma, an operation which many coffee lovers insist on performing themselves. A good roaster must be a part artist, and part scientist, to maintain quality and consistency. In the development of flavours, roasting is probably the most important of the steps considered so far. Well roasted coffee should be brown, of varying degrees of darkness, but never black. Both traditional and modern roasters are used, but in order to get better uniform quality of roasted beans, modern (electric) roasters are preferred. The roasting process causes the coffee beans to swell and increase their size by over 50%, while at the same time greatly reducing their weight (Hicks, 2002).

Temperature and time are two critical things that have to keep in mind during roasting to obtain better quality coffee. During roasting, the coffee beans are heated at 200-2400 C about 10-15 minutes depending on the degree of roasting required, which is mainly evaluated by colour. The amount of oil drawn to the surface of the bean due to caramelization of sugar and carbohydrates inside the bean increases proportionately to the length of roasting time. After roasting, coffee does not keep its aroma for long; it is, therefore, better not to roast or not to buy coffee exceeding current needs. It is advisable to keep it in airtight package-aging to prevent light, heat and moisture ingress (Deoju and Manandhar, 2004).

2.3.3.4 Grinding

This is the last operation through which coffee bean has to go before being actually made cup for brewing. In order to avoid the loss of aroma, coffee should be ground immediately before being made for brewing purpose as aroma is quickly lost from ground coffee (Hicks, 2002). In Nepal, traditional grinding using wooden or marble mortars with a pestle are common. Electric grinders are also used by some coffee exporting companies.

2.4 Quality attributes

Quality attributes are the result of various product properties, which are noticeable by sensory observation or via communication, and in this way contribute to the quality perception and experience of consumers and costumers. The intrinsic-extrinsic model is the basis for selection and classification of the different quality attributes (Figure 2.9). The model distinguishes

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between two different types of quality attributes i.e. intrinsic and extrinsic, both of which can influence the acceptance of the products. The intrinsic attributes are inherent to the physical product whereas extrinsic attributes do not necessarily have a direct relationship with the product properties but can affect consumers’ quality perceptions which are mainly related to production and marketing aspects of a product (Lunning and Marcelis, 2009).

Although eating quality is a combination of characteristics, attributes and properties that lead to enjoyment, consumers say that appearance and freshness are most important in initial purchase. The select products that are the appropriate colour, size, and shape, with the proper firmness. Expectation of nutritional value and health-enhancing properties are also of importance (Bruhn, 2002).

2.4.1 Quality attributes in coffee

Coffee is drunk for pleasure; its flavour is, therefore, the most important quality criterion. It is the sum of different parameters all coming into play during primary production of green coffee bean. Criteria used to measure quality of green beans are bean size, shape of bean, density, color and the bean chemistry of the raw bean. These criteria are influenced by a wide range of factors like plant genetics, orchard practices and postharvest treatment. All the downstream operations (storage, roasting, brewing) can only preserve cup quality. Besides its flavour characteristics, other factors such as environmental impact, purity and safety are becoming important for the global evaluation of coffee quality (Viani, 2001).

The most important quality parameters are ripeness of cherry and time to processing. The coffee may give an astringent or impure cup, if harvested immature or kept too long before processing. Careful picking, collecting, and storing of cherries should be précised to produce high quality coffee. Coffee cherries should be stored in the shadow because in the full sun cherries will start to ferment earlier (Njoroge, 2004).

Analytical (moisture content and defective bean count) and organoleptic (taste testing) criteria are generally used by the coffee roaster to determine the choice of the green coffee beans. Moreover, quality evaluation for the roaster requires reliability of supply, uniform low moisture and agreed defect count, regular roasting characteristics and of course the cupping quality (Laderach, 2007).

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Figure 2.9 Intrinsic-extrinsic quality attributes model (Source: Luning and Marcelis, 2009)

Consumers’ quality perception

Noticeable product attributes

Intrinsic attributes Extrinsic attributes

• Safety (microbial, chemical, physical) • Health (nutritional value, health

compounds)

• Sensory (texture, taste, odour, colour)

• Shelf life (keepability, freshness • Convenience (easy to use, to

prepare)

• Product system characteristics • Assigned quality by

marketing/communication

Physicochemical properties of raw materials and products

• Variable composition • Dynamic food processes • Variable genetic characteristics

Technological factors • Process parameters

• Equipment properties

• Building and facility characteristics • Environmental conditions

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2.4.2.1 Moisture content determination

This is the analytical measurement with regards to quality assessment in coffee associated with water content inside coffee seeds.

According to International Coffee Council (ICC) Resolution number 420, for both Arabica and Robusta coffees, a moisture content range of 9-12% has been recommended in order to adopt the quality standards for exported coffees (ICO, 2004). If a moisture percentage below 12% has currently been received, coffee exporting members can work with set purpose in order to ensure that this level is maintained or decreased.

Exceptions to the 12% maximum limit can be permitted for specialty coffees which traditionally have high moisture percentages e.g. Indian coffees harvested during monsoon season. Such kind of coffees can be clearly noticed by specific grade nomenclature (origin, growing condition) (ICO, 2004).

2.4.2.2 Defective bean counts and cup tasting

In general quality determination of green coffee bean can be done in three main categories: coffee grading, sensory evaluation and analytical measurements. In grading the main objective is to determine the size distribution of the coffee along with the assessment of the defective beans and their colour. Sensory evaluation focuses on determining the flavour profile while analytical measurements can determine moisture percentage, chemical composition and possible pesticide residues (Wintgens, 2004).

Bean size play an important role for roasted whole coffee beans because many consumers associate bean size with quality, however, larger beans do not necessarily taste better than smaller one. It has to be pointed out that for roasting, the more uniform the bean size, the better the heat transfer and consequently the roast. The amount of defective beans is also associated with quality. Larger amount of imperfections will increase the probability of finding off-flavours and lesser homogeneity in the cup, but low amounts of visible defects do not necessarily correlate higher cup quality. The assessment of defective beans count is done by hand picking all defects from a specified amount of coffee, then grouping similar defects, counting and weighting them (Piechaczek, 2009). According to New York Exchange Board (NYBOT), as shown in Tables 2.1 and 2.2, to qualify as exchange grade coffee, 9 to 23 full defects per 300 g sample of green beans are permitted and 50% of the coffee by weight must be above screen size 15 (6 mm = medium) and only less than 5% below screen size 14 (5.5 mm = small).

Table 2.1 NYBOT Classification system in coffee quality assessment Classes Description of full defects allowed in each class Class 1 Specialty grade (0-5 full defects)

Class 2 Premium grade (6-8 full defects) Class 3 Exchange grade (9-23 full defects) Class 4 Below standard grade (24-86 full defects) Class 5 Off grade (more than 86 full defects) Source: ICO, 2004

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Similarly, specialty coffee refers to class 1 in which no primary defects are permitted, and only 5% by weight can be above or below the indicated screen size, which implies that the customer chooses according to his preferences (Table 2.2).

Table 2.2 Quality requirements for different grades of coffee

Exchange Grade (9-23 full defects) Specialty Grade (0-5 full defects) Primary defects permitted, 50% by weight

above screen size 15, less than 5% below screen size 14

No primary defects, 5% above below indicated screen size

No faults permitted, 5 quakers permitted No faults and taints, no quakers

Sound cup, good roasting Most possess at least one distinctive attribute in the body, aroma or acidity

Source: ICO, 2004

Cup tasting is also the way to evaluate the coffee in an objective and reproducible way. Its main objective is to describe the flavour profile by attributes and values related to the intensity of each attribute, seek objectivity. Only trained coffee experts can judge coffee by this method. This kind of assessment, in some way, is inevitably subjective, since it is based above all on personal experience and memory. The basic attributes evaluated in cup tasting are: aroma, flavour, body and acidity (Deoju and Manandhar, 2004).

Wintgens (2004) in his literature defined the terms that are frequently used to assess the cup characteristics of coffee include:

Aroma: the fragrance or odour perceived by nose of freshly ground coffee and in cup aroma after 4 minute contact with hot water.

Taste: perceived by the tongue

Flavour: combination of aroma and taste. The flavour is described in terms of winey, spicy and fragrant. Off flavours, such as grassy, onion, musty or earthy reduce coffee quality.

Body: feeling of heaviness or richness on tongue.

Acidity: sharp and pleasing taste. It can range from sweet to fruity and is considered as a favourable attribute. Also roasting has an effect on acidity, the more intense the roasting, the more acidity is affected.

2.5 Quality management systems

Good quality produce is very important to consumers and retailers, and it is a key factor consumer’s use in evaluating a supermarket. High quality produce is second only to a clean, neat store as top factors in selecting a supermarket. High quality fruits and vegetables are rated very important by all income and geographic groups, but they are especially valued among the highest income households (Bruhn, 2002).

It is important to realize that the physicochemical properties of products for consumption are the result of a complex food production chain where various technological conditions and many quality decisions contribute to final food quality. It is necessary to look at this from a chain perspective because it gives some insight into where and how to take design, control,

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improvement and or assurance measures to realize physicochemical properties and related attributes that comply with consumer demands (Luning and Marcelis, 2009).

With respect to food safety control and assurance, processing can often eliminate many pathogens and spoilage micro-organisms but heat stable toxins, many environmental contaminants and various residues cannot be removed by processing. Their occurrence should be kept below certain limits by preventive measures as early in the food production chain as possible.

It becomes apparent that it is not always clear what belongs to quality management system and what not. The boundaries between quality management systems and other management systems (market) of the firm (enterprise, company) are blurring. Information structures that are created for the transfer of information about quality compliance are increasingly used for the transfer of all kinds of products and process related information. One should note that the term ‘best practice’ quality management system depends on the market a firm is operating in (Plaggenhoef et al., 2009). At the bottom of the market in particular quality regulations are regarded as something firms have to comply with and the perception exists that it should do as little as possible for the assurance of quality.

2.5.1 Quality management in coffee processing

Coffee beans and ground coffee are more likely to be attacked by toxicogenic fungi as compared to cherries and parchment if not stored properly. Although the issue of time of invasion of coffee by toxicogenic fungi has not been properly carried out, this is of great importance in understanding the problem of Ochratoxin A (toxin produced by the fungus

Aspergilus) in coffee and developing control strategies. Experiences have shown that if invasion

occurs during preharvest operation, control will be much more difficult than if it occurs postharvest, i.e. during drying and storage of dry cherry, parchment, green beans and ground coffee. Postharvest problems seem to be appeared due to unfavourable climates for drying, poor drying practice, quality control or inadequate storage conditions (Taniwaki et al., 2003).

Moisture content (MC) and water activity (aw) are the most important factors that influence fungal growth in coffee bean. To avoid the development of toxicogenic fungi in coffee, the water activity should be kept under control from postharvest to final processing. Drying coffee beans to 11-12% moisture content, which corresponds to water activity (aw) of 0.60, avoids subsequent fungal growth and consequently Ochratoxin A production. Coffee roasting can remove level of Ochratoxin A to a significant percentage i.e. 20-60% reductions. However, depending on the roasting process, the residual Ochratoxin A percentage in coffee may differ from 0-100% (FAO, 2008).

Coffee processing and trading company has to put in place a system to assure quality standards for coffee all the way from its pulping centres, through the milling process, to the market. It should check for the size and maturity of the coffee cherries and moisture levels of parchment and also grade the coffee using special grading machine and a trained specialist in the processing factory who are responsible to check that the green beans are unbroken and free of foreign particles to ensure good quality control system (KIT and IIRR, 2008).

2.6 Coffee value chain

A value chain is a specific type of supply chain one where the actors actively seek to support each other so they can increase their efficiency and competitiveness. They invest time, effort

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and money and build relationships with other actors to reach a common goal of satisfying consumer needs so they can increase their profits (KIT et al., 2006).

Value chain map of coffee in Kavre district includes the linkages of many actors from the input supply up to the consumers. Different actors, their roles and interrelationship among them fall under the scope of the chain map (Annex B).

Some of the coffee industries in Nepal do all the activities from the production of seedlings to pulping, hulling and even export covering the entire chain. These industries are not specializing their roles but exporting small volumes of green beans by performing all the roles from seedling production to all kinds of processing. The exportable product is costly due to the fact that all the functions such as pulping, fermentation, hulling, drying, roasting, grinding and exporting are done by a single enterprise in small volume (Tiwari, 2009).

Value chain of coffee in Nepal is not well defined and is still unorganized owing to the reasons of low volume of production. Before 2000 A.D., most of the coffee production was concentrated only in the Western region of the country and farmers were dependent on few coffee processing factories to sell their fresh cherries which have resulted in a sort of monopoly in the coffee market. In recent years, with the gradual increase in the area, production and demand, many processing companies, private and run by farmers’ cooperatives, have been emerged (Sapkota, 2007).

In Nepal, most of the coffee is processed by wet method i.e. 75%, however dry processing methods is still in practice (25%) in rural areas where transportation is major problem and farmers are not accessed by pulping machines. More farmers have been showing interest towards wet processing methods as the price premium for the parchment coffee is higher (Koirala, 2003).

2.7 Quality management in coffee supply chain

Coffee farmers union has greater power in controlling the chain activities such as logistics, processing, marketing and exporting. It has capability to negotiate on prices, coordinates the producers and organizes the quality control throughout the chain (KIT et al., 2006). An expert from the agricultural department checks the quality of coffee bean brought by cooperative to the processing factory for moisture content and colour.

Wet processing is more controlled technique than dry processing, and produces better quality coffee, which fetches better prices (KIT and IIRR, 2008). Coffee processing company has greater role to create a sustainable business by improving the end-quality of dried coffee beans through better post-harvest processing techniques. Coffee cherries are bulky in nature, perishable product which has to be processed quickly.

The striking emergence of dynamic markets for certified organic, fair trade and eco-friendly coffees firmly place the coffee industry at the forefront in developing innovative responses that are relevant to the difficulties of the rural development and trade in coffee producing countries (Giovannuci, 2003).

In Nepal, improvement in quality of coffee through the supply chain not only depends on coffee production management system adopted by the coffee producers, but also on postharvest on-farm quality management system. Lack of appropriate equipment (pulping machine) and well

Comparitve analysis of dry and wet processing of coffee with respect to quality in Kavre District, Nepal

COMPARATIVE ANALYSIS OF DRY AND WET PROCESSING OF

COFFEE WITH RESPECT TO QUALITY IN KAVRE DISTRICT, NEPAL

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